Fluidic and/or gate

ABSTRACT

A fluidic gate having AND and exclusive OR outputs is disclosed in which the switching sensitivity of the gate is selectively determined by simple changes in the interior geometry of the gate.

United States Patent Inventor App]. No.

Filed Patented Assignee Anthony J. Healey State College, Pa.

Jan. 9, 1970 Dec. 14, 1971 Bell Telephone Laboratories, IncorporatedMurray Hill, Berkeley Heights, NJ.

FLUlDlC AND/OR GATE 17 Claims, 5 Drawing Figs.

U.S.Cl

lnLCl [50] Field ofSearch l37/8l.5

[56] References Cited UNITED STATES PATENTS 3.285.265 11/1966 Boothe etal 137/815 Primary Examiner-William R. Cline Attorneys-R. J. Guentherand Edwin B. Cave ABSTRACT: A fluidic gate having AND and exclusive ORoutputs is disclosed in which the switching sensitivity of the gate isselectively determined by simple changes in the interior geometry of thegate.

PATENTEDUEBHIQR 3,626,965

SHEET 1 OF 3 FIG.

//v VENTOR ANThg NVJ HE AL E V A 7'TOR/VE V PATENIEB 051:1 419718,626,965

sum 3 OF 3 noz SWITCHING SENSITIVITY 0 Q I 1 I I.0b L5 b 2.0b 2.5b 3.0b3.5b 4.0b

OFFSET DISTANCE d r'wmrc AND/R GATE This invention relates to fluidiclogic devices and more particularly to fluidic half-adder gates.

BACKGROUND OF THE INVENTION Fluidic half-adder gates may be used toprovide the logic functions of AND" and exclusive OR." Such devices havetwo input ports from which pressurized fluid jets selectively issue.Either jet, appearing alone and exclusively of the other, will bereceived at a first fluid output. Thus an exclusive OR function isindicated by a fluid flow from the first output. The concurrence of thetwo jets causes a second fluid output to receive the resultant of theinteracting jets. An AND logic function is therefore indicated by fluidflow from this second output.

Such devices are now in general commercial use and were disclosed insuch prior patents as US. Pat. No. 3,285,265 issued to W. A. Boothe etal. on Nov. 15, 1966, and US. Pat. No. 3,338,5 l 5, issued to E. M.Dexter on Aug. 29, 1967. However, none of the prior devices provides anymethod for controlling the switching sensitivity of the device.Switching sensitivity may be defined as the ratio of the pressures inthe two inputs at which the pressure in one input is just high enough toswitch the jet at the other input from the 0R output to the AND output.

Switching sensitivity is an essential consideration in the selection ofcomponents for a fluidic system. If the device is too sensitive, smallspurious signals (noise) or impedance mismatches in the system may causeundesired switching of the device. At the other extreme, if the deviceis too insensitive, it may fail to properly switch in response tolow-level input signals.

The optimum switching sensitivity is also a function of the intendedapplication. Obviously if the input jets have relatively high pressureof constant magnitude and the spurious flows are small, an insensitivegate would be much more applicable than if the jets were low pressure,or if the pressure varied widely, or if the signal-to-noise" ratio islow. The system designer must therefore select a device having aswitching sensitivity that properly balances the risk of inadvertentswitching against the risk of a failure to switch when required.

It is, therefore, an object of my invention to provide simple means forselecting the switching sensitivity of such devices so that a devicehaving the optimum sensitivity may be provided for each application.

SUMMARY OF THE INVENTION In an illustrative embodiment of my invention awall is provided in the chamber where the two jets interact which helpsposition the output jets. By locating this wall at a desired andpredetermined position relative to the input jets, the desired switchingsensitivity may be obtained.

DESCRIPTION OF THE DRAWING FIG. 1 is a plan view of a device embodyingby invention;

FIG. 2 shows the device of FIG. .1 with the fluid flow path indicatedfor a first input jet alone;

FIG. 3 shows the device of FIG. 1 with the fluid flow path indicated fora second input jet alone;

FIG. 4 shows the device of FIG. I with the fluid flow path indicated forthe two concurrent jets; and

FIG. 5 shows the graphical relationship between the switchingsensitivity and the location of the positioning wall.

DESCRIPTION OF THE ILLUSTRATIVE EMBODIMENT Fluid logic devices may beconstructed from any rigid, nonporous material, including glass,ceramic, plastic and metal. Such devices generally comprise a base, intowhich the desired passages are impressed or etched, and a coverproviding a fluidtight seal which is secured to the base by any of anumber of methods, such as adhesives, fasteners, clamps, or the like.

For ease of the illustration, the drawings of FIGS. 1-4 depict a devicehaving a glass cover. This was done to permit the interior of the deviceto be shown without the confusing presence of cross section lines. Thisshould in no way be interpreted as a limitation on the materialssuitable for use in the device, since any rigid, nonporous material isapplicable.

The particular device illustrated in FIG. 1 comprises a first fluidinput, passage 101, and a second fluid input, passage 102, which connectto independent fluid pressure sources (not shown). These sources providepressurized fluid selectivity, depending upon system conditions. Theinlets I0! and 102 communicate respectively with flow-restrictingnozzles 104 and 105 which are substantially perpendicular to each other.The nozzles act to generate a fluid jet when fluid pressure is presentat the respective inlet. The dimensions indicated on the FIGURE will beexplained later in detail.

Fluid logic devices of this type usually rely on the Coanda effect, alsocalled the wall attachment phenomenon. This phenomenon results when afluid jet flows past a wall. The unattached jet traps ambient fluidbetween the jet and the wall, resulting in a reduction of pressure inthe entrainment region. Turbulence increases the entrained flow and theresulting pressure difi'erential across the jet causes the jet to movecloser to the wall.

The closer the jet comes to the wall, the greater this force imbalancebecomes. Regenerative efl'ects cause the jet to rapidly assume a stablestate in which the imbalance forces are minimized. The minimum imbalancestate occurs when equilibrium is attained. This occurs when therestraining force exerted by the wall on the jet equals the imbalanceforce. When this point is reached, the jet has moved so close to thewall, and the forces acting on it have become so strong, that the jet iseffectively "attached" to the wall. To break the attachment, equilibriummust be disturbed to such an extent that attachment is broken and aseparation of the jet from the wall occurs. Separation occurs at a pointand then propagates along the wall until the entire jet is unlocked.

The flow lines in FIG. 2 represent the jet pattern in device 100 whenpressurized fluid is present at inlet I01 alone. The exclusive jetissues from nozzle 104 and flows past wall 107. Under the phenomenonjust described, the jet attaches itself to wall 107. After flowing pastwall 107, the jet is deflected by the curved wall 108. When the jetleaves wall 108, at cusp 109, it has been redirected in a generallydownward direction. The jet continues in a relatively straightdirection, with the jet diverging slightly, since there is no adjacentwall to which the jet may attach and be supported.

The jet is deflected once again, this time by wall area 112, so that itis received at an output port, receiver 1 14. Fluid flow into conduit118, whose inlet is receiver 114, is indicative of an exclusive OR"condition, in this case flow from input 101 in the absence of flow frominput 102. Any loading effects, or flow resulting from impedancemismatches in the system, which could cause back pressure at receiver114, is relieved by providing a vent 117 either to the atmosphere orback to the fluid pressure reservoir, depending on the fluid being used.

If pressurized fluid were present at input 102, but not at input 101,the flow pattern of FIG. 3 would be established. The same entrainmentwall attachment condition described above will cause the jet from nozzle105 to attach to wall section 111. The attached jet will then followwall 1 12 to receiver 114. This is also indicative of the exclusive ORcondition since flow is present from input 102 in the absence of flowfrom input 101. Vent 117 again provides for the release of jet fluidunder high load conditions so that the device is maintained at, or near,atmospheric or tank pressure and the integrity of the jet is maintainedfor all loading conditions.

The resultant jet placement when flow is present at both inputs does notdepend upon wall attachment, as previously described. As shown in FIG.4, if a jet is concurrently present at both nozzles I04 and 105, eachwill act upon the other. A momentum exchange occurs in which each jetdeflects the other from its normal direction. The two deflected jetscombine to form a singe resultant jet at an intermediate angle to theoriginal jets.

The curved wall section 108 provides a pocket" in which a circulation isestablished by the flow of the resultant jet. The circulation creates ahigher pressure region near the intersection with wall 107 to hold theresultant jet away from deflecting wall 108 and prevent any deflectiontowards output 14. At the same time, a lower pressure region is createdwithin the circulation region, which is dependent upon the position ofthe edge of the jet relative to cusp 109. This phenomenon, known asknife edge attachment," creates a force to position the resultant jetneat the cusp. A second, circulation is created as the resultant jetflows past cusp 109. This circulation, resulting from the knife edgeattachment at cusp 109, causes the resultant jet to be guided toreceiver 115. The presence of fluid flow through receiver 1 15 intoconduit 119 provides the AND logic function and indicates thesimultaneous presence of pressurized fluid at inputs 101 and 102. Vent117 provides for high load conditions as previously described.

The action of the jets within the device is a function of the relativeinternal geometry of the device. Since the actual dimensions of thedevice have relatively little significance, this discussion will be interms of relative dimensions using the width b of nozzles 104 and 105 asa unit measure.

The length y of wall 1 11 is normally approximately equal to b. Iflength y were less than b, the wall surface presented to a v jet fromnozzle 105 would be insufficient to provide good attachmentcharacteristics. At the other extreme, if y became too long, the wall111 would provide a very strong attachment to the jet making itdifficult to switch the jet off the wall. This in effect would make thedevice approach the relatively insensitive device in which a is Theconsequences of this will be discussed later.

- The radius R of wall 108 normally approximates 2b. If a smaller radiusis used, insufficient space is provided for guiding a jet of width bfrom nozzle 104 and changing is direction. As a result, a highlyturbulent condition is created and the jet becomes fragmented. If theradius is increased, less pressure is required for a jet at nozzle 104to switch a jet from wall 111 towards receiver 115 making the devicehypersensitive, as well as making it difficult to obtain a strongattachment to wall 1 12 under the flow condition shown in FIG. 3.

Angle 0 is optimized at approximately 45 if nozzles 104 and 105 areapproximately perpendicular. Since the resultant of two equal andperpendicular jets would travel away at a bisecting angle, receiver 1 15would most effectively be placed along the bisector. If it were placedto either side of the bisector, only a percentage of the resultant jetwould be received and the balance would spill over into vent region 117.Of course, the angle B between nozzles 104 and 105 could be varies tochange the bisector. However, if B were less than 90, the separationbetween the AND and OR outputs would be decreased, thereby increasingthe possibility of a jet causing an unintended effect at the wrongoutput. If B were greater than 90, the jets would have an undesirableeffect on each other caused by the jet being partially directed backthrough the other orifice.

The length L of wall 112 is nominally 13b. If the length is increased,the dispersion of the jet before it reaches receiver 114 increases andcauses loss of pressure recovery. Decreasing the length of wall 112results in the deflected jet of FIG. 2 being "focused" at a point beyondreceiver 114. Once again, a disruption of the regular jet flow occursand pressure recovery is low.

The effects of the angle a of wall 112 and the length d of wall 107 maybe understood by referring to FIG. 5 which shows graphically therelationship between a, d and switching sensitivity P /P Switchingsensitivity is the ratio between the pressure in one jet required toswitch the other jet from the OR output to the AND output and thepressure in the other jet. Stated in numerical terms, if a jet isissuing from nozzle 104 with a pressure of l0 p.s.i. at input 101, and ajet issuing from nozzle 105 having a pressure of l psi. at input 102 isrequired to switch the resultant jet from receiver '1 14 to receiver115, the switching sensitivity of the device is l/lOor 0.10. Pressuresbelow this critical value will deflect the other jet but it willreattach itself to the wall after passing the nozzle.

Highly sensitive devices appear at the bottom of FIG. 5 and relativelyinsensitive devices appear towards the top. It should also be borne inmind that although the curve for B=20 appears fairly flat, thesensitivity change is from approximately 0.075 to approximately 0.125,which represents a decrease in sensitivity of approximately 67 percent.

The angle a of wall 112 determines how "tightly" the jet from nozzleattaches to wall 112. As 1: decreases, the attachment increases and itbecomes more difficult to switch the jet. Therefore, as 41 decreases, adevice becomes less sensitive. High values of a result in highlysensitive devices. In this respect, the selection of a value of a by afluidic system designer is analogous to a rough selection or "coarseadjustment."

The "fine tuning is provided by selecting a value for the length d ofwall 107. If wall 107 is very short, or not present at all, the forcedue to wall attachment exerted on a jet from nozzle 105 by the shortwall 107 is minimal. Hence, small variations in the length of wall 107when d is less than b have little corresponding effect of the switchingsensitivity.

lf wall 107 is very long, curved wall 108 becomes so far displaced fromnozzles 104 and 105 that it cannot exert a meaningful influence on thejets. The force that wall 108 exerts on the resultant AND jet is slight,and as a result, variations in the length of wall 107 where d is greaterthan 4b also have only minimal effect on the switching sensitivity.Thus, it can be seen that only in the approximate range of d greaterthan b but less than 4b is it possible to make a meaningful selection ofthe suitable sensitivity.

Using my invention, a fluidics system designer may determine theswitching sensitivity he needs for a device in a particular application.Then, by consulting FIG. 5, he may choose the particular value of anglea necessary to yield the approximate sensitivity necessary. He thenselects a value of displacement d to yield the specific sensitivitydesired. The needed device may then be constructed in accordance withthe selected values. Thus, the optimum switching sensitivity may beprovided for each device in the system.

Only representative curves for a=0, a=l0 and a=20 are shown in FIG. 5.It should, however, be readily apparent that similar curves, for othervalues of a, are within the scope of 'the family of curves respectivelyshown.

Despite the fact that the embodiment describes a passive device, itshould also be apparent that the inventive principles are equallyapplicable to an active device in which either input is continuouslypresent and the active output is determined by the presence or absenceof a control jet at the other input.

It should be apparent that my invention could also be applied tofabricate a device having a variable sensitivity. If walls 107 and 108were fabricated from a deformable material, or if wall 107 werepositioned along an adjustable track, the displacement d could be variedwhen desired. However, since the optimum switching sensitivity of adevice in a particular application does not change, the more usualapplication of my invention will probably be in selectively fabricatingnonadjustable devices.

What is claimed is:

1. A fluidic logic device having a predetermined switching sensitivitycomprising a first aperture for generating a first fluid jet,

a second aperture adjacent the first aperture for generating a secondfluid jet transverse to the axis of the first jet,

an OR receiver positioned to receive the generated first jet in theabsence of the second jet,

an AND receiver positioned to receive a resultant jet produced byconcurrent generation of the first and second jets, and

a walled chamber in which the concurrently generated first and secondjets interact, a first wall of the chamber including an initial section,adjacent the first aperture and having a length exceeding the width ofthe first aperture, to which the second jet attached itself and a curvedsection separated from the first aperture by the initial section forredirecting the attached jet to be received at the OR receiver and forpositioning the resultant jet to be received by the AND receiver, thecurved section being located relative to the first and second aperturesin accordance with a predetennined relationship for imparting thedesired switching sensitivity to the device.

2. A device in accordance with claim 1 further including a second wall,positioned intermediate the first and second apertures and the Rreceiver, to which the first jet attaches in the absence of the secondjet and to which the redirected second jet attaches in the absence ofthe first j the second wall being positioned relative to the axis of thefirst jet in accordance with a second predetermined relationship toimpart the desired switching sensitivity to the device.

3. A device in accordance with claim 2 wherein the second predeterminedrelationship is shown by FIG. in which angle n represents the divergencebetween the second wall and the axis of the first jet.

4. A device in accordance with claim 1 wherein the predetenninedrelationship is shown by F IG. 5 in which distance d represents thedistance between the curved section means and the first aperture.

5. A device in accordance with claim 5 wherein distance d varies betweenb and 4b, where b is the width of the first aperture.

6. A fluidic logic device having a predetermined switching sensitivitycomprising a first aperture for generating a first fluid jet,

a second aperture adjacent the first aperture for generating a secondfluid jet transverse to the axis of the first jet,

an OR receiver positioned to receive the generated first jet in theabsence of the second jet,

an AND receiver positioned to receive the resultant jet produced by theconcurrent generation of the first and second jets,

means for redirecting the second jet in the absence of the first jet sothat the second jet is received at the OR receiver,

a first wall located between the redirecting means and the first andsecond apertures to which the second jet attaches in the absence of thefirst jet, and

a second wall, positioned intennediate the first and second aperturesand the OR receiver, to which the first jet attaches in the absence ofthe second jet and to which the redirected second jet attaches in theabsence of the first jet,

the second wall being positioned relative to the axis of the first jetin accordance with a predetermined relationship to impart the desiredswitching sensitivity to the device.

7. A device in accordance with claim 6 wherein the predeterminedrelationship is shown by FIG. 5 where angle a represents the divergencebetween the second wall and the axis of the first jet.

8. A device in accordance with claim 6 wherein the redirecting means islocated relative to the first and second aperture in accordance with asecond predetermined relationship for imparting the desired switchingsensitivity to the device.

9. A device in accordance with claim 8 wherein the second predeterminedrelationship is shown by FIG. 5 in which distance d represents thelength of the first wall and the distance between the redirecting meansand the first aperture.

10. A device in accordance with claim 9 wherein distance d variesbetween b and 4b, where b is the width of the first aperture.

11. A fluidic logic device having a predetermined switching sensitivitycomprising a first fluid passage,

a first flow restrictor communication with the first passage forgenerating a first fluid jet in response to fluid flow in the firstpassage,

a second fluid passage,

a second flow restrictor communicating with the second passage andadjacent the first restrictor for generating a second fluid jet along anaxis transverse to the axis of the first jet in response to fluid flowin the second passage,

a first receiver positioned to receive either jet in the absence of theother jet,

a first fluid conduit communicating with the first receiver for issuinga fluidic signal indicative of an exclusive OR logical function inresponse to the receipt of a jet by the first receiver,

a second receiver positioned to receive a resultant jet produced by theconcurrent generation of the first and second jets,

a second fluid conduit communicating with the second receiver forissuing a fluidic signal indicative of an AND logical function inresponse to the receipt of a jet by the second receiver, and

a multiwalled chamber communicating with the first and secondrestrictors and the first and second receivers,

a first wall of the chamber being located so that either jet, in theabsence of the other jet, attaches thereto and is delivered to the firstreceiver,

a second wall of the chamber being located so that the second jet, inthe absence of the first jet, is redirected from its normal axis toattach to the first wall and so that the resultant jet is positioned tobe received by the second receiver, the second wall including a sectionadjacent the first restrictor to which the second jet attaches in theabsence of the first jet, and

a curved section abutting the section adjacent the first restrictor forboth positioning the resultant jet and for redirecting the second jetfrom its normal axis to another axis in the absence of the first jet,

the location of the first and second walls being in accordance with apredetermined relationship to impart the desired switching sensitivityto the device.

12. A fluidic logic device having a predetermined switching sensitivitycomprising a first fluid passage,

a first flow restrictor communicating with the first passage forgenerating a first fluid jet in response to fluid flow in the firstpassage,

a second fluid passage,

a second flow restrictor communicating with the second passage andadjacent the first restrictor for generating a second fluid jet, alongan axis transverse to the axis of the first jet, in response to fluidflow in the second passage,

a first receiver for receiving either jet in the absence of the otherjet,

a first fluid conduit communicating with the first receiver forproducing an exclusive OR fluidic logic signal in response to receipt ofa jet by the first receiver,

a second receiver for receiving a resultant jet produced by theconcurrent generation of the first and second jets,

A second fluid conduit communicating with the second receiver forproducing an AND fluidic logic signal in response to receipt of a jet bythe second receiver,

a walled chamber communicating with the first and second restrictors andincluding a first wall section, adjacent the second restrictor andparallel to the axis of the first jet, to which the first jet attachesin the absence of the second jet,

a second wall section, adjacent the first restrictor and parallel to theaxis of the second jet, to which the second jet attaches in the absenceof the first jet,

a third wall section contiguous to the second section for deflecting thejet attached to the second section away from its normal axis to analtered axis which intersects the normal axis of the first jet,

a cusp contiguous to the third section for positioning the resultant jetto be received at the second receiver, and

a fourth wall section contiguous to the first section to which thealtered jet attaches and for delivering to the first receiver both thealtered jet and the jet attached to the first wall section, and

a vent passage located between the first and second receiver forrelieving fluid pressure in the chamber, and wherein the length of thesecond wall section, and the resulting location of the third wallsection relative to the first and second restrictors, is in accordancewith a first predetermined relationship and the angle of divergencebetween the fourth wall section and the axis of the first jet is inaccordance with a second predetermined relationship for imparting adesired and predetennined switching sensitivity to the device.

13. A device in accordance with claim 12 wherein the first and secondpredetermined relationships are shown by FIG. in which distance drepresents the distance between the third'wall section and the firstrestrictor and angle or represents the divergence between the fourthwall section and the axis of the first jet.

14. A device in accordance with claim 13 wherein distance d variesbetween b and 4b, where b is the width of the first restrictor.

15. A device in accordance with claim 11 wherein the section adjacentthe first restrictor has a length exceeding the width of the firstrestrictor, the length being determined by the placement of the curvedsection of the second wall relative to the first restrictor,

the angle of divergence between the first wall and the axis of the firstjet determines the placement of the first wall and the predeterminedrelationship is shown by FIG. 5 where distance d represents the distancebetween the first restrictor and the curved wall, and angle a representsthe divergence between the first wall and the axis of the first jet.

16. A device in accordance with claim 15 wherein distance d variesbetween b and 4b, where b is the width of the first restrictor.

17. A fluidic logic device having a predetermined switching sensitivitycomprising a first aperture for generating a first fluid jet,

a second aperture adjacent the first aperture for generating a secondfluid jet transverse to the axis of the first jet,

an OR receiver positioned to receive the generated first jet in theabsence of the second jet,

an AND receiver positioned to receive a resultant jet produced by theconcurrent generation of the first and second jets, and

a walled chamber wherein the generated first and second jets interactand which includes a first wall section, adjacent the second aperture,to which the first jet attaches in the absence of the second jet,

a second wall section, adjacent the first aperture, to which the secondjet attaches in the absence of the first jet,

a third wall section contiguous to the second section for deflecting thejet attached to the second section away from its normal axis to analtered axis which intersects the normal axis of the first jet,

a cusp contiguous to the third section for positioning the resultant jetto be received at the AND receiver, and

a fourth wall section contiguous to the first section and at a divergingangle to the axis of the first jet to which the altered jet attaches andfor delivering both the altered jet and the jet attached to the firstwall section to the OR receiver,

the length of the second wall section, and the resulting location of thethird wall section relative to the first and second apertures, is inaccordance with a first predetermined relationship and the angle ofdivergence between the fourth wall section and the axis of the first jetis in accordance with a second predetermined relationship for impartinga desired and predetermined switching sensitivity to the device.

I 1 i i UNITED STATES PATENT OFFICE CERTIFICATE ()F CORRECTION PatentNo. 3, 626, 965 Dated December 1 1971 Inventor-(s) Anthony J. Healey Itis certified that error appears in the above-identified patent and thatsaid Letters Patent are hereby corrected as shown below:

Column 1, line 58, change "by" to -my- Column 3, line 7, change "1 1" to"11 1"; line 12, change "neat" to "nearline 12, before "circulation"insert -sma11er-; line 37, change "is" to its; lines 51 and 52, change"varies" to -varied Column line 7, change "6" to a; line 24, change "of"to on-; line 34, change "suitable" to switching; line 71, before"concurrent" insert --the. Column 5, line 3, change "attached" toattaches; line 28, delete "means"; line 29, change "5" to t"; line 62,change "aperture to -apertures--. Column 6, line 1, change"communication" to -communicating-; line 59, change "A" to -a. Column 7,line 5, change "receiver" to receivers-.

Signed and sealed this 20th day of June 1972.

(SEAL) Attest:

EDWJ TRQMJLETQLERJR. ROBERT GOTISCHALK Attesting Officer Commissioner ofPatents FORM PO-ZOSO (10-69) USCOMM-DC 60376-P69 u.s. GOVERNMENTPRINTING OFFICE: i969 0-366-334

1. A fluidic logic device having a predetermined switching sensitivitycomprising a first aperture for generating a first fluid jet, a secondaperture adjacent the first aperture for generating a second fluid jettransverse to the axis of the first jet, an OR receiver positioned toreceive the generated first jet in the absence of the second jet, an ANDreceiver positioned to receive a resultant jet produced by theconcurrent generation of the first and second jets, and a walled chamberin which the concurrently generated first and second jets interact, afirst wall of the chamber including an initial section, adjacent thefirst aperture and having a length exceeding the width of the firstaperture, to which the second jet attaches itself and a curved sectionseparated from the first aperture by the initial section for redirectingthe attached jet to be received at the OR receiver and for positioningthe resultant jet to be received by the AND receiver, the curved sectionbeing located relative to the first and second apertures in accordancewith a predetermined relationship for imparting the desired switchingsensitivity to the device.
 2. A device in accordance with claim 1further including a second wall, positioned intermediate the first andsecond apertures and the OR receiver, to which the first jet attaches inthe absence of the second jet and to which the redirected second jetattaches in the absence of the first jet, the second wall beingpositioned relative to the axis of the first jet in accordance with asecond predetermined relationship to impart the desired switchingsensitivity to the device.
 3. A device in accordance with claim 2wherein the second predetermined relationship is shown by FIG. 5 inwhich angle Alpha represents the divergence between the second wall andthe axis of the first jet.
 4. A device in accordance with claim 1wherein the predetermined relationship is shown by FIG. 5 in whichdistance d represents the distance between the curved section means andthe first aperture.
 5. A device in accordance with claim 4 whereindistance d varies between b and 4b, where b is the width of the firstaperture.
 6. A fluidic logic device having a predetermined switchingsensitivity comprising a first aperture for generating a first fluidjet, a second aperture adjacent the first aperture for generating asecond fluid jet transverse to the axis of the first jet, an OR receiverpositioned to receive the generated first jet in the absence of thesecond jet, an AND receiver positioned to receive the resultant jetproduced by the concurrent generation of the first and second jets,means for redirecting the second jet in the absence of the first jet sothat the Second jet is received at the OR receiver, a first wall locatedbetween the redirecting means and the first and second apertures towhich the second jet attaches in the absence of the first jet, and asecond wall, positioned intermediate the first and second apertures andthe OR receiver, to which the first jet attaches in the absence of thesecond jet and to which the redirected second jet attaches in theabsence of the first jet, the second wall being positioned relative tothe axis of the first jet in accordance with a predeterminedrelationship to impart the desired switching sensitivity to the device.7. A device in accordance with claim 6 wherein the predeterminedrelationship is shown by FIG. 5 where angle Alpha represents thedivergence between the second wall and the axis of the first jet.
 8. Adevice in accordance with claim 6 wherein the redirecting means islocated relative to the first and second apertures in accordance with asecond predetermined relationship for imparting the desired switchingsensitivity to the device.
 9. A device in accordance with claim 8wherein the second predetermined relationship is shown by FIG. 5 inwhich distance d represents the length of the first wall and thedistance between the redirecting means and the first aperture.
 10. Adevice in accordance with claim 9 wherein distance d varies between band 4b, where b is the width of the first aperture.
 11. A fluidic logicdevice having a predetermined switching sensitivity comprising a firstfluid passage, a first flow restrictor communicating with the firstpassage for generating a first fluid jet in response to fluid flow inthe first passage, a second fluid passage, a second flow restrictorcommunicating with the second passage and adjacent the first restrictorfor generating a second fluid jet along an axis transverse to the axisof the first jet in response to fluid flow in the second passage, afirst receiver positioned to receive either jet in the absence of theother jet, a first fluid conduit communicating with the first receiverfor issuing a fluidic signal indicative of an exclusive OR logicalfunction in response to the receipt of a jet by the first receiver, asecond receiver positioned to receive a resultant jet produced by theconcurrent generation of the first and second jets, a second fluidconduit communicating with the second receiver for issuing a fluidicsignal indicative of an AND logical function in response to the receiptof a jet by the second receiver, and a multiwalled chamber communicatingwith the first and second restrictors and the first and secondreceivers, a first wall of the chamber being located so that either jet,in the absence of the other jet, attaches thereto and is delivered tothe first receiver, a second wall of the chamber being located so thatthe second jet, in the absence of the first jet, is redirected from itsnormal axis to attach to the first wall and so that the resultant jet ispositioned to be received by the second receiver, the second wallincluding a section adjacent the first restrictor to which the secondjet attaches in the absence of the first jet, and a curved sectionabutting the section adjacent the first restrictor for both positioningthe resultant jet and for redirecting the second jet from its normalaxis to another axis in the absence of the first jet, the location ofthe first and second walls being in accordance with a predeterminedrelationship to impart the desired switching sensitivity to the device.12. A fluidic logic device having a predetermined switching sensitivitycomprising a first fluid passage, a first flow restrictor communicatingwith the first passage for generating a first fluid jet in response tofluid flow in the first passage, a second fluid passage, a second flowrestrictor communicating with the second passage and adjaCent the firstrestrictor for generating a second fluid jet, along an axis transverseto the axis of the first jet, in response to fluid flow in the secondpassage, a first receiver for receiving either jet in the absence of theother jet, a first fluid conduit communicating with the first receiverfor producing an exclusive OR fluidic logic signal in response toreceipt of a jet by the first receiver, a second receiver for receivinga resultant jet produced by the concurrent generation of the first andsecond jets, A second fluid conduit communicating with the secondreceiver for producing an AND fluidic logic signal in response toreceipt of a jet by the second receiver, a walled chamber communicatingwith the first and second restrictors and including a first wallsection, adjacent the second restrictor and parallel to the axis of thefirst jet, to which the first jet attaches in the absence of the secondjet, a second wall section, adjacent the first restrictor and parallelto the axis of the second jet, to which the second jet attaches in theabsence of the first jet, a third wall section contiguous to the secondsection for deflecting the jet attached to the second section away fromits normal axis to an altered axis which intersects the normal axis ofthe first jet, a cusp contiguous to the third section for positioningthe resultant jet to be received at the second receiver, and a fourthwall section contiguous to the first section to which the altered jetattaches and for delivering to the first receiver both the altered jetand the jet attached to the first wall section, and a vent passagelocated between the first and second receiver for relieving fluidpressure in the chamber, and wherein the length of the second wallsection, and the resulting location of the third wall section relativeto the first and second restrictors, is in accordance with a firstpredetermined relationship and the angle of divergence between thefourth wall section and the axis of the first jet is in accordance witha second predetermined relationship for imparting a desired andpredetermined switching sensitivity to the device.
 13. A device inaccordance with claim 12 wherein the first and second predeterminedrelationships are shown by FIG. 5 in which distance d represents thedistance between the third wall section and the first restrictor andangle Alpha represents the divergence between the fourth wall sectionand the axis of the first jet.
 14. A device in accordance with claim 13wherein distance d varies between b and 4b, where b is the width of thefirst restrictor.
 15. A device in accordance with claim 11 wherein thesection adjacent the first restrictor has a length exceeding the widthof the first restrictor, the length being determined by the placement ofthe curved section of the second wall relative to the first restrictor,the angle of divergence between the first wall and the axis of the firstjet determines the placement of the first wall and the predeterminedrelationship is shown by FIG. 5 where distance d represents the distancebetween the first restrictor and the curved wall, and angle Alpharepresents the divergence between the first wall and the axis of thefirst jet.
 16. A device in accordance with claim 15 wherein distance dvaries between b and 4b, where b is the width of the first restrictor.17. A fluidic logic device having a predetermined switching sensitivitycomprising a first aperture for generating a first fluid jet, a secondaperture adjacent the first aperture for generating a second fluid jettransverse to the axis of the first jet, an OR receiver positioned toreceive the generated first jet in the absence of the second jet, an ANDreceiver positioned to receive a resultant jet produced by theconcurrent generation of the first and second jets, and A walled chamberwherein the generated first and second jets interact and which includesa first wall section, adjacent the second aperture, to which the firstjet attaches in the absence of the second jet, a second wall section,adjacent the first aperture, to which the second jet attaches in theabsence of the first jet, a third wall section contiguous to the secondsection for deflecting the jet attached to the second section away fromits normal axis to an altered axis which intersects the normal axis ofthe first jet, a cusp contiguous to the third section for positioningthe resultant jet to be received at the AND receiver, and a fourth wallsection contiguous to the first section and at a diverging angle to theaxis of the first jet to which the altered jet attaches and fordelivering both the altered jet and the jet attached to the first wallsection to the OR receiver, the length of the second wall section, andthe resulting location of the third wall section relative to the firstand second apertures, is in accordance with a first predeterminedrelationship and the angle of divergence between the fourth wall sectionand the axis of the first jet is in accordance with a secondpredetermined relationship for imparting a desired and predeterminedswitching sensitivity to the device.